Conventionally, the drive unit having a rotating electric machine and a controller for controlling the rotating electric machine, i.e., for driving the rotating electric machine is known. The controller of the drive unit has a substrate on which electronic components, e.g. a relay, a capacitor, and other electronic components, are mounted, and the substrate has terminals connected thereto for the wiring from the rotating electric machine, a power supply, and the like.
For the connection between the substrate and the terminal, a press-fit connection method which does not use soldering is known may be performed. The press-fit connection method may, for example, forcefully insert a terminal that has a resiliently-deformable press-fit portion into a piercing hole of the substrate which has a plated inner surface or into a piercing hole of a bus-bar that is mounted on the substrate. See for example a disclosure of a patent document, Japanese Patent Laid-Open No. JP 2007-326379 A (patent document 1).
However, the length of the piercing hole of a substrate which accommodates the press-fit portion of the terminal or the length of the piercing hole of the bus-bar is equal to the thickness of the substrate or the bus-bar, i.e., no substantial tolerance allowed for the positioning of the terminal in the course of inserting the terminal into the piercing hole of the substrate. In other words, an insertion work for inserting the press-fit portion of the terminal must have a high positioning accuracy. That is, the robustness of the connection between the substrate and the terminal is low.
Specifically, in the drive unit in which the terminal for an electrical connection to the rotating electric machine or to a power supply is required to be connected to the substrate, the assembly work for establishing a connection between the substrate and the terminal should be highly accurate for a reliability of the product.